Drew Brees smiles when he discusses his rapport with his receivers. How he knows Marques Colston and Lance Moore will break off or alter routes without verbal communication, how a glance at Jimmy Graham on what is supposed to be a running play transforms into a first-down reception.

During offseason workouts, younger receivers marvel at this NFL version of ESP. Then they go to Brees, the Saints’ all-pro quarterback coming off his third 5,000-yard campaign.

Um, that wasn’t in the playbook?

Sorry, young fellas. Still gotta learn it.

“It’s probably frustrating in the beginning because you’re like, ‘Ah, I don’t do that; why did he do that?’ ” Brees said, still smiling. “But I just tell those guys that it will come. It’s just time and repetition.”

It’s perhaps the biggest challenge this offseason for third-year receiver Joe Morgan, second-year pro Nick Toon and rookie Kenny Stills, who headline a group of young players vying for the No. 3 receiver job made available when the Saints opted to not re-signed Devery Henderson. They must learn not only the offensive playbook but sudden, often unannounced route changes that can’t be found on a sheet of paper.

Brees calls it “feel.” The guy who does it best has a clearer path to becoming the new guy in last season’s top-ranked passing offense.

“It’s going to make for a heck of a training camp,” said Moore, who last season caught 65 passes for 1,041 yards with six touchdowns. “That competition should bring out the best in all of us.”

Last season, Brees passed for 5,177 yards and 43 TDs with 19 interceptions.

Graham said Brees learns body movements not only through practice repetition but film study.

That preparation has helped Graham evolve from a college basketball player to a Pro Bowl tight end with the potential to be one of the best ever at his position.

It’s familiarity that has allowed Colston to catch 58 TDs from Brees, the most by an active quarterback/receiver duo. Time together has transformed Moore from an undrafted free agent to a multi-millionaire.

“Oh, it’s serious,” Graham said. “Just little, hint things.”

Halfway through last season, Morgan earned a part-time membership to the receiving crew, thanks to his 48-yard touchdown reception at Tampa Bay. Morgan has the best understanding of Brees of all the young receivers, although he spent his rookie season on injured reserve.

“When you get out on the field and guys start moving around, he knows what they’re going to do instead of being robotic with what’s on paper,” said Morgan, who is coming off a 10-catch, 379-yard season with three TDs. “Everything happens so fast. It’s crazy how he knows all that.”

Toon, a 2012 fourth-round pick, spent last season on injured reserve (foot). He said he feels like he has caught up physically from the time he missed last season. Now he’s looking to follow the path of Colston and Moore.

“Those guys have been here for a long time,” Toon said. “A lot of what they’ve accomplished comes with time and experience, even just going out there and making plays.”

Stills was selected in the fifth round of April’s draft. Already he has gained insight to how the receivers are able to bond with Brees.

“Comes with the extra throws after practice,” Stills said. “Comes with making a mistake here and there and Drew being able to tell me, ‘Hey, this is where I want you; this is how you’re supposed to do it.’